C(17,13,4) = 7

Method of Construction: simple construction: added element to c(v-1,k-1,t) covering

Lower Bound: Mills, Covering Designs I, 1979

  1  3  4  7  8  9 10 11 12 13 14 15 17
  2  5  6  7  8  9 10 12 13 14 15 16 17
  1  2  3  4  5  6  7  8 11 14 15 16 17
  1  2  4  5  6  8  9 10 12 13 14 16 17
  2  3  5  6  8  9 10 11 12 13 14 16 17
  1  2  3  4  5  6  7 10 11 12 15 16 17
  1  2  3  4  5  6  7  9 11 13 15 16 17